1. Field of the Invention
The present invention relates to a hydraulic control system of a power train for a hybrid vehicle, in more detail, a hydraulic control technology for controlling a power train of a hybrid vehicle which can implement two or more power split modes and three or more fixed-stage modes.
2. Description of Related Art
FIG. 1 illustrates the configuration of a power train of a hybrid vehicle using the present invention, which includes an engine Engine, a first motor generator MG1, and a second motor generator MG2. Further, a first planetary gear set PG1 and a second planetary gear set PG2 are provided to receive from the engine and the motor generators, such that the output for the driving wheels comes from the second planetary gear set.
The planetary gear set is a singe pinion planetary gear set including a first sun gear S1, a first carrier C1, and first ring gear R1 and the second planetary gear set is a single pinion planetary gear set including a second sun gear S2, a second carrier C2, and a second ring gear R2, in which the second carrier is directly connected with the first ring gear and connected to the driving wheels through an output member Output.
Total four operating members are connected to the rotary members of the first planetary gear set and the second planetary gear set to restrict rotation of the rotary members, such that it is possible to implement various driving modes with the engine, the first motor generator, and the second motor generator, as shown in FIG. 2.
That is, a first brake BK1 is connected to first sun gear S1, a second brake BK2 is connected to second ring gear R2, a first clutch CL1 is connected between first carrier C1 and second ring gear R2, a second clutch CL2 is connected between first carrier C1 and second sun gear S2, engine Engine is connected to first carrier C1, first motor generator MG1 is connected to first sun gear S1, second motor generator MG2 is connected to second sun gear S2, such that it is possible to implement various driving modes, in accordance with the operational states of first brake BK1, second brake BK2, first clutch CL1, and second clutch CL2, which are the operating members, the engine, and the first motor generator and the second motor generator.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.